Antimony doped tin oxide (ATO) has excellent optoelectronic properties. To obtain a small particle size and well-dispersed nano ATO materials in the drying process is a critical step in the preparation. In this paper

the supercritical drying time

temperature

pressure and CO2 flow rate were studied as the main parameters affecting the nano ATO particle's size and specific surface area. In addition

the kinetic equations of drying curve were fitted. ATO nano particles with average particle size of 20-30 nm and high specific surface area of 75-80 m2·g-1 were obtained with the supercritical CO2drying process parameters: temperature (35-40℃)

pressure (10-14 MPa)

CO2 flow rate (1.2-1.8 L·h-1)

drying time (5-6 h); and alcohol gel drying process could be divided into three stages: rising speed

uniform speed and decreasing speed. There was a critical point in the alcohol ratio (MR) of alcoho gel

and when MR was smaller than 0.4

drying slowed down from uniform speed to decreasing speed. However

large supercritical flow rate could not obviously increase drying rate on the other hand. In addition

the Weibull function was used to describe the kinetics of supercritical CO2 drying process of alcohol gel. As a result

the kinetic model was built and the drying process could accurately be described by the Weibull function. The results could provide helpful reference for industrial production and control of wet gel dried by supercritical CO2 in the preparation of well-dispersed nano particles.